The European Union sent Javier Solana, its foreign policy chief, to Skopje last night to urge the Macedonian government to try to keep a dangerously escalating situation under control, as fighting between ethnic Albanian rebels and security forces spread yesterday.

Nato's secretary general, Lord Robertson, joins him today as western countries scramble to contain the worsening crisis one of only two former Yugoslav republics to have been spared full-scale conflict.

Mr Solana will travel to Kosovo's capital, Pristina, today to urge its Albanian leaders to distance themselves from their rebel Macedonian kinsmen.

EU foreign ministers meeting in Nykoping, Sweden, urged the Macedonian government not to declare a state of war and to continue the inter-ethnic dialogue it promised with the country's Albanian minority.

Anna Lindh, the Swedish foreign minister, and the EU external relations commissioner, Chris Patten, are to go to the Macedonian capital, Skopje, later in the week to drive home the same message.

Last month the EU signed a landmark "stabilisation and association agreement" with Macedonia which the member states want to use as a carrot to encourage dialogue between Slavs and Albanians. It was the first time in the bloody 10-year history of the break up of Yugoslavia that the EU seemed to have a useful independent role to play.

Helicopter gunships, tanks and mortars were used to pound the villages of Slupcane and Vaksince again yesterday after the expiry of a deadline for civilians to leave the area.

The attack came as the rebels showed no sign of withdrawing from their positions in the north-west, where security forces bombarded them for a fourth day running. A senior rebel chief swore that his men would not leave the region, as rebel units had done near Tetovo more than a month ago when attacked by the army.

"We'll never let Tetovo happen again," said Commander Sokhu, speaking at his headquarters near Slupcane.

The International Committee of the Red Cross expressed serious concern for people living in the area. At least seven people - all civilians according to the rebels - have been killed in fighting since last Thursday.

A government spokesman said two police checkpoints were attacked by gunmen north of the city of Tetovo. Rebel chiefs said their forces clashed with the army near the village of Shatka, close to the Kosovo border, and explosions could be heard miles away.

The ongoing conflict has boosted support in government circles for a declaration of war. The prime minister, Ljubco Georgievski, said he hoped the measure would give the security forces a free hand to deal with the crisis. The declaration would allow President Boris Trajkovski to form a new government and effectively rule by decree.

However, observers said that while the idea was being discussed, Mr Trajkovski was per sonally opposed to the move.

The declaration of a state of war would need a two-thirds majority in the Macedonian parliament and would be bitterly opposed by ethnic Albanian MPs, with whom the government has been negotiating to form a new coalition.

In Slupcane, villagers huddled in cellars as the bombardment began after the expiry of the deadline to evacuate.

Surrounded by up to 50 members of his extended family, Alidin Osmani, 50, said villagers had given up listening to the government's deadlines since his cousin, Rumsi Osmani, had been killed. "He was outside on Thursday afternoon and 10 minutes before the deadline was due to expire he was killed by a mortar," Mr Osmani said.

Outside the Osmani home, a stream of dried blood could be seen where he was killed. "They gave us an ultimatum and an hour after announcing it they started shelling us. What kind of ultimatum is that?" he said.

The government claims that the families remaining in the villages are being used as human shields by the rebels, but Mr Osmani said it was the fear of the Macedonian police that was keeping them from leaving the house. "Where can we go. If we go the Macedonians will be waiting for us. They will separate the men from the children," he said. "Here the women are afraid and the children are crying."

Out on the street not a single house was left untouched by the shelling. Two dead horses and a cow lay by the side of the road. The walls were pockmarked and any windows left uncovered were smashed. The fantails of mortar shells lay dotted along the road. One shell had blasted out the side of a house.

A rebel staff car, a Russian jeep with the letters UCK sprayed on its sides, shot by. The guerrillas claim to have 2,000 men in 12 villages around Kumanovo. Rebel checkpoints and bunkers can be seen at the entry to each village. They wear either black or khaki uniforms, all of them with a red badge bearing the group's initials.

Commander Sokhu said his men moved into the area from their bases near the border with Kosovo after the Macedonian army's offensive in Tetovo. Amid all the surrounding destruction and stress on the villagers he said his men could not be blamed for what was happening.